(19)
(11) EP 0 233 533 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
03.02.1988 Bulletin 1988/05

(43) Date of publication A2:
26.08.1987 Bulletin 1987/35

(21) Application number: 87101384

(22) Date of filing: 02.02.1987
(84) Designated Contracting States:
AT BE CH DE ES FR GB GR IT LI NL SE

(30) Priority: 18.02.1986 US 829900
05.03.1986 US 836664

(71) Applicant: AMERICAN CYANAMID COMPANY
 ()

(72) Inventor:
  • Ryles, Roderick Glyn
     ()

   


(54) Mobility control reagents with superior thermal stability


(57) Homopolymers of 2-acrylamido-2-methylpropane sul­fonic acid or its salts or copolymers thereof with N,N-­dimethylacrylamide are used to maintain the viscosity of aqueous solutions thereof in the presence of poly­valent salt containing-waters during the enhanced re­covery of petroleum from subterranean petroleum-bearing deposits.





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